In recent years, various types of recording mediums used to record digital data have been developed and used. For example, as optical discs, compact discs have been become common. The standard for the compact discs (CD) is referred to as compact disc digital audio (CD-DA). The CD standard is based on the description of the relevant standard document called Red Book. So far, on the basis of the standard document, various types of formats such as CD-ROM standard have been standardized as so-called CD family. In the following description, CD represents CD-DA disc.
The CD family includes reproduction-only type optical discs such as a CD and a CD-ROM (Compact Disc-Read Only Memory) disc and writable record and reproduction type optical discs such as CD-R (Compact Disc-Recordable) disc and a CD-RW (Compact Disc-Rewritable). Once data is written to a CD-R disc, the written data cannot be erased therefrom. After data has been written to a CD-R disc, the written data cannot be rewritten thereto. However, in the present patent application, a CD-R is categorized as a writable record and reproduction type optical disc.
Among them, reproduction-only type optical discs such as a CD and a CD-ROM disc have been widely used to record digital data of commercial software and so forth. For example, at the present time, many CDs for music software and CD-ROM discs for games, programs, and video software have been sold. As the reason why software of digital data is sold with CDs or CD-ROM discs, it is thought that as described above they are reproduction-type optical discs and they can be quantitatively and inexpensively produced in a short time.
Since many users have already had recording and/or reproducing apparatuses that can reproduce those CDs or CD-ROM discs, it is thought that an environment for distributing software as digital data with CDs or CD-ROM discs will not be largely changed.
However, when software of digital data is recoded with CDs or CD-ROM discs, the following problems arise.
At present, data that is read from a reproduction-only optical disc such as a CD or a CD-ROM disc can be easily copied to a writable record and reproduction type optical disc such as a CD-R disc or a CD-RW disc with a recording and reproducing apparatus, copy software, and so forth. However, since a CD was developed as a reproduction-only recording medium, a conventional reproducing apparatus or a conventional recording and reproducing apparatus that reproduces data from a CD, a CD-ROM disc, a CD-R disc, and a CD-RW disc do not have a function for determining whether data that has been reproduced from a disc is original data or copied data. Thus, they can reproduce data from a CD-R disc and a CD-RW disc onto which data has been copied. It is difficult to determine whether or not the current disc is an original disc or a copied disc with the appearance thereof. In such an environment, it was difficult to effectively protect data from being illegally copied. In other words, it was difficult to protect copyright of information recorded on a CD, a CD-ROM disc, and so forth.
Since mediums such as a CD and a CD-ROM disc and their drivers have been widely used, it is difficult to newly add a copy protection function.
Therefore, an object of the present invention is to provide a method for controlling access to data of a disc and a method for determining a disc that allow copyright of data recorded on mediums such as a CD and a CD-ROM disc to be protected without need to largely change the current standards and apparatuses.